Liquid crystal display device

ABSTRACT

A height difference under a sealant is reduced in a case where lines are present under the sealant.  
     There is provided a substrate having an active matrix display circuit and peripheral driving circuits, a counter substrate having a counter electrode provided on the substrate in a face-to-face relationship therewith, a sealant provided between the substrate and the counter substrate such that it surrounds the active matrix display circuit and peripheral driving circuits, a liquid crystal material provided inside the sealant, a plurality of external connection lines provided on the substrate under the sealant with a resin inter-layer film interposed therebetween for electrically connecting the active matrix display circuit and peripheral driving circuits to circuits present outside the sealant and an adjustment layer provided in the same layer as the plurality of external connection lines.

[0001] The present invention relates to a structure of a liquid crystaldisplay device integral with peripheral circuits in which an activematrix display circuit and peripheral driving circuits are provided onthe same substrate.

[0002] More particularly, the present invention relates to aconfiguration in which peripheral driving circuits are provided inside aregion enclosed by a sealant for sealing a liquid crystal material.

[0003] There are configurations of liquid crystal display devicesintegral with peripheral circuits having an active matrix circuit andperipheral driving circuits provided on the same substrate in whichperipheral driving circuits are provided inside a region enclosed by asealant for sealing the liquid crystal material. A CPU, a memory, acontrol circuit and the like may be provided in addition to peripheraldriving circuits.

[0004] In such a device, lines are provided under the region where thesealant is provided (hereinafter referred to as “sealant region”). Forexample, such lines include external connection lines for transmittingsignals between the outside and inside of the sealant and short ringsformed by extending scanning lines and signal lines and shorting themoutside the sealant region in order to prevent electrostatic breakdownof TFTs (thin film transistors) forming an active matrix display circuitat manufacturing steps.

[0005] The lines provided under the sealant region results in differentheights in the sealant. Such a height difference is primarily caused bytwo reasons.

[0006] One reason is that the lines under the sealant region arelocalized and are not present in some locations.

[0007] The other reason is that the line width and line intervals of thelines under the sealant region vary.

[0008]FIG. 13 shows an example of a liquid crystal display deviceintegral with peripheral driving circuits. Referring to FIG. 13, asubstrate 1501 and a counter substrate 1502 are disposed in aface-to-face relationship with a sealant 1505 having an injection hole1510 interposed therebetween to form a panel. On the substrate 1501,there is provided an active matrix display circuit 1503, peripheraldriving circuits such as shift registers and decoders for driving thecircuit 1503 and external connection lines 1508 for electricallyconnecting those circuits and circuits outside the sealant to transmitsignals therebetween.

[0009] The external connection lines 1508 are connected to the externalcircuits through an FPC (flexible printed circuit).

[0010] There is further provided short rings 1509 which are formed byextending scanning lines and signal lines. The short rings 1509 areformed to short those lines with each other outside the sealant regionto prevent electrostatic breakdown of TFTs (thin film transistors)forming the active matrix display circuit at manufacturing steps. Theconfiguration of the short rings 1509 shown in FIG. 13 is aconfiguration for multi-shot manufacture in which a plurality of panelsare obtained from a single substrate. Although not shown in FIG. 13, theshort rings are electrically connected to the short rings of an adjacentpanel to short the scanning lines and signal lines, and the short ringsare separated when the substrate is separated into independent panels asshown in FIG. 13.

[0011]FIG. 14A shows sections of a region under the sealant 1505 wherethe external connection lines 1508 are provided and a region where noline is provided. Referring to FIG. 14A, provided on the substrate 1501are an underlying film 1511 such as a silicon oxide film, a firstinter-layer film 1512 formed by a silicon oxide film, a silicon nitridefilm or a multi-layer film consisting of them, external connection lines1508 and a resin inter-layer film 1513 made of resin such as polyimideor acrylic.

[0012] The external connection lines 1508 are formed by a metal film,e.g., an aluminum film, in the range from about 200 nm to 700 nm.Although dependent on the, application, the external connection lines1508 are formed by a plurality of lines each having a width in the rangefrom 50 μm to 300 μm provided as a group at intervals in the range from30 μm to 100 μm.

[0013] In such a configuration, the resin inter-layer film 1513 has athickness of about 1 μm and is provided in order to achieve flatness.However, regions of the resin inter-layer film 1513 having the externalconnection lines 1508 is higher than regions having no line by a heightdifference d. Such a step can be in the range from a few hundred nm to500 nm, although it is smaller than the height (thickness) of theexternal connection lines 1508.

[0014]FIG. 14B shows a sectional view of a region under the sealant 1505where the short rings 1509 are provided in the same layer and using thesame material as those of the external connection lines 1508. Therefore,the thickness (height) of the short rings 1509 is the same as that ofthe external connection lines 1508. The short rings are extensions ofsignal lines and scanning lines. They are a plurality of lines eachhaving a width in the range from 2 μm to 10 μm provided as a group atintervals in the range from 20 μm to 100 μm.

[0015] There is a height difference d2 between the region where theshort rings 1509 are provided and the region where the externalconnection lines 1508 are provided. This height difference can be alsoin an approximate range from a few hundred nm to 500 nm. Especially, theheight difference is increased when a plurality of the resin inter-layerfilms are formed. A step on the order of 1000 nm may be formed when thefilms are stacked to a thickness on the order of 2 μm.

[0016] A step can be formed on the resin inter-layer film also betweenthe region having the short rings 1509 and the region having no line.

[0017] The substrate having the active matrix display circuit providedthereon and the counter circuit are provided in a face-to-facerelationship with a sealant including spacers (spherical or cylindricalmicroscopic particles for maintaining an interval between thesubstrates) interposed therebetween. Therefore, any uneven heightdifference in the sealant region where the sealant is provided causesdistortion of the counter substrate such as flexing and twisting to makethe substrate interval uneven. As a result, a uniform state of displaycan not be achieved in a single screen and there will be unevenness incolor and brightness.

[0018] The problem of the distortion of the substrate does not occureven in the presence of a height difference under the sealant region ifthe height difference is uniformly distributed under the sealant region.However, since the lines extending across the sealant region areprovided as a group of lines which are locally concentrated, in general,such a height difference is not uniformly distributed under the sealantregion. This results in distortion of the substrate as described above.

[0019] The allowance (the range in which no uneven display occurs) forthe height difference under the sealant region is on the order of only1000 nm for a TN (twisted nematic) type liquid crystal display.Especially, for an ECB (electrically controlled multi-reflectivity) modeutilizing nematic liquid crystal, a height difference of only 200 nmcauses distortion of the substrate which leads to uneven display andcolor variation. For example, a height difference of 200 nm between theexternal connection lines and the short rings makes the substrateinterval in the vicinity of the short rings smaller than that in thevicinity of the external connection lines, thereby causing distortion ofthe substrate and uneven display. Therefore, it is quite important for aliquid crystal display device to have a small height difference underthe sealant region in order to provide uniform display in one screen.

[0020] It is an object of the present invention to reduce a heightdifference under a sealant region where wiring is provided under thesealant region (sealant).

[0021] Especially, it is an object of the present invention to reduce aheight difference under a sealant region in a configuration whereinwiring is provided under the sealant region and one or more inter-layerfilms made of a resin material are provided on the wiring.

[0022] It is another object of the present invention to reduce a heightdifference under the sealant region in a configuration wherein lineshaving different widths are provided under the sealant region andwherein one or more inter-layer films made of a resin material areprovided above those lines.

[0023] According to the present invention, a liquid crystal displaydevice comprises:

[0024] a first substrate having a active matrix circuit and peripheraldriving circuits provided thereon;

[0025] a counter substrate having a counter electrode provided in aface-to-face relationship with the substrate;

[0026] a sealant provided between the first substrate and the countersubstrate such that it surrounds the active matrix circuit andperipheral driving circuits;

[0027] a liquid crystal material provided inside the sealant;

[0028] a plurality of external connection lines provided on the firstsubstrate under the sealant with a resin inter-layer film interposedtherebetween for electrically connecting the active matrix displaycircuit and peripheral driving circuits to circuits present outside thesealant; and

[0029] an adjustment layer provided in the same layer as the pluralityof external connection lines.

[0030] In the above-described configuration, the adjustment layer may beprovided with the same thickness as that of the plurality of externalconnection lines.

[0031] In either of the above-described configurations, the adjustmentlayer may be provided with the same intervals and width as those of theplurality of external connection lines.

[0032] In any of the above-described configurations, at least one of theplurality of external connection lines may be electrically connected inparallel to one of a plurality of auxiliary lines provided in a layerdifferent from that of the external connection lines to reduceelectrical resistance, and an adjustment layer may be provided in thesame layer as the auxiliary lines.

[0033] A plurality of lines extending across the sealant thereunder andhaving a smaller width than that of each of the plurality of externalconnection lines and intervals greater than the width may be provided ina layer different from that of the plurality of external connectionlines, and the plurality of lines may include extensions from scanninglines and signal lines that form the active matrix display circuit.

[0034] Further, a plurality of lines extending across the sealantthereunder and having a smaller width than that of each of the pluralityof external connection lines and intervals greater than the width may beprovided in the same layer as that of the plurality of externalconnection lines, and the plurality of lines may include extensions fromscanning lines and signal lines that form the active matrix displaycircuit. The plurality of lines may include a portion under the sealantwhere the width is increased.

[0035] In the configuration in which at least one of the plurality ofexternal connection lines is electrically connected in parallel to oneof a plurality of auxiliary lines provided in a layer different fromthat of the plurality of external connection lines to reduce electricalresistance and in which an adjustment layer is provided in the samelayer as the auxiliary lines:

[0036] a plurality of first lines having a width smaller than that ofeach of the plurality of auxiliary lines may be provided at intervalsgreater than the width in the same layer as the auxiliary lines suchthat they extend across the sealant thereunder;

[0037] the plurality of first lines may include extensions of either thescanning lines or signal lines forming the active matrix displaycircuit;

[0038] the plurality of first lines have a portion under the sealantwhere the width thereof is increased;

[0039] a plurality of second lines having a width smaller than that ofeach of the plurality of auxiliary lines may be provided at intervalsgreater than the width in the same layer as the auxiliary lines suchthat they extend across the sealant thereunder;

[0040] the plurality of second lines may include extensions of the otherof group of lines, i.e., the scanning lines or signal lines forming theactive matrix display circuit; and

[0041] the plurality of second lines have a portion under the sealantwhere the width thereof is increased.

[0042] In the above-described configuration, the extensions of eitherthe scanning lines or signal lines forming the active matrix circuit maybe provided in a face-to-face relationship with the adjustment layerprovided in a layer different from that of either the scanning lines orsignal lines.

[0043] Further, the adjustment layer may have a region under the sealantin a face-to-face relationship with the extension of either the scanninglines or signal lines, which is electrically separated from adjacentregions.

[0044] Furthermore, the adjustment layer may be electrically dividedinto a plurality of segments in the region in a face-to-facerelationship with the extensions of either the scanning lines or signallines.

[0045] The extensions of the other group of lines, i.e., either thescanning lines or signal lines forming the active matrix display circuitmay be provided in a face-to-face relationship with an adjustment layerprovided in a layer different from that of the other group of lines,i.e., the scanning lines or signal lines.

[0046] In addition, the adjustment layer may have a region facing theextension of either the scanning lines or signal lines, which iselectrically separated from adjacent regions.

[0047] Moreover, the adjustment layer may be electrically divided into aplurality of segments in the region facing the extensions of either thescanning lines or signal lines.

[0048] According to the principle of the present invention, regionsunder a sealant are adjusted to a height similar to that of the highestregion under the sealant.

BRIEF DESCRIPTION OF THE DRAWINGS

[0049]FIG. 1 shows a configuration of an embodiment of the presentinvention.

[0050]FIGS. 2A and 2B show the configuration of the embodiment of thepresent invention.

[0051]FIGS. 3A and 3B show a configuration of another embodiment of thepresent invention.

[0052]FIGS. 4A and 4B show a configuration of still another embodimentof the present invention.

[0053]FIG. 5 shows a configuration of still another embodiment of thepresent invention.

[0054]FIGS. 6A and 6B show the configuration of the embodiment of thepresent invention.

[0055]FIGS. 7A and 7B show the configuration of the embodiment of thepresent invention.

[0056]FIGS. 8A and 8B show the configuration of the embodiment of thepresent invention.

[0057]FIGS. 9A and 9B show a configuration of still another embodimentof the present invention.

[0058]FIGS. 10A and 10B show a configuration of still another embodimentof the present invention.

[0059]FIGS. 11A and 11B show a configuration of still another embodimentof the present invention.

[0060]FIG. 12 shows a configuration of still another embodiment of thepresent invention.

[0061]FIG. 13 shows a configuration of an example of a liquid crystalpanel.

[0062]FIGS. 14A and 14B show the cross section of the liquid crystalpanel of FIG. 13.

[0063]FIGS. 15A through 15F show examples of the application of thepresent invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0064] Preferred embodiments of the present invention will now bedescribed with reference to the accompanying drawings.

EXAMPLE 1

[0065] The present embodiment refers to an example of flattening of asealant region to eliminate a height difference in a configurationwherein external connection lines are provided under the sealant region.

[0066]FIG. 1 shows a configuration of an active matrix display circuitaccording to the present embodiment.

[0067] Referring to FIG. 1, a substrate 101 and a counter substrate 102are disposed in a face-to-face relationship with a sealant 105 having aninjection hole 110 interposed therebetween to form a panel. Provided onthe substrate 101 are an active matrix display circuit 103, peripheraldriving circuits 104 such as shift registers and decoders for drivingthe circuit 103 and external connection lines 108 for electricallyconnecting those circuits to circuits (not shown) outside the sealant totransmit signals therebetween. The external connection lines 108 areconnected to the external circuits through an FPC (flexible printedcircuit). Both of the active matrix circuit and the driving circuit maybe formed on the substrate using thin film transistors as disclosed by apending application Ser. No. 08/879,583 (filed on Jun. 20, 1997) forexample. The entire disclosure of the application Ser. No. 08/879,583 isincorporated herein by reference.

[0068] Referring again to FIG. 1, the peripheral driving circuits 104have a redundant configuration wherein two driving circuits are providedfor each of signal lines and scanning lines.

[0069] In FIG. 1, there is provided an adjustment layer 106 whichextends along the sealant 105 in continuation to the region under thesealant 105 with an inter-layer film (not shown) interposed in the samelayer as that of the external connection lines but in a region where theexternal connection lines 108 are not present.

[0070]FIG. 2A shows an enlarged view of the region A 109 in FIG. 1, andFIG. 2B shows a sectional view taken along the line A-A′ in FIG. 2A.

[0071] Referring to FIG. 2A, a plurality of external connection lines108 having a predetermined width w1 are provided in a concentrated groupat predetermined intervals w2. According to the present embodiment, thewidth w1 is in the range from 50 μm to 300 μm and is 200 μm for example.The intervals w2 are in the range from 30 μm to 100 μm and is 50 μmhere.

[0072] Referring to FIG. 2B, a first inter-layer film 112 and a resininter-layer film 113 are provided on the substrate 101 made of glass,quartz, silicon wafer or the like with an underlying film 111constituted by a silicon oxide film or the like interposed therebetween,and a sealant 105 is provided thereon. An orientation film (nor shown)may be provided between the sealant 105 and the resin inter-layer film113.

[0073] As apparent from FIG. 2B, the external connection lines 108 andan adjustment layer 106 are formed between the first inter-layer film112 and resin inter-layer film 113 in the same layer and using the samematerial such as aluminum. Therefore, the adjustment layer 106 has thesame thickness (height) as the external connection lines 108 such thatregions under the inter-layer film 113 where the external connectionlines 108 are not present have the same height as the externalconnection lines 108.

[0074] Such a configuration reduces the difference in height between aregion having the external connection lines 108 and a region having noexternal connection line on the upper surface of the resin inter-layerfilm 113 under the region where the sealant 105 is provided. This alsoreduces distortion of the counter substrate when it is put together.Further, uniform display without variation can be achieved in onescreen.

[0075] While the adjustment layer 106 has a configuration like acontinuous lines, the external connection lines have intervals w2. As aresult, a height difference can occur because the region including theexternal connection lines 108 in the region under the sealant 105 isslightly lower than the region where the adjustment layer 106 isprovided. However, since the width w1 of the external connection lines108 is sufficiently greater than the intervals w1 between the lines,such a height difference is quite small and does not cause unevendisplay.

[0076] The external connection lines 108 and the adjustment layer 106may be provided in a layer different from that of the signal lines(source lines) of the TFTs forming the active matrix display circuit andperipheral driving circuits, although they are in the same layer in theconfiguration of the present embodiment.

[0077] The external connection lines 108 and adjustment layer 106 may beprovided in different layers with the same thickness, which is stillsimilarly effective as providing them in the same layer. For example,the adjustment layer 106 may be provided under the first inter-layerfilm 112, and the external connection lines 108 may be provided abovethe first inter-layer film 112. Alternatively, their positions may bereversed. When the external connection lines 108 and adjustment layer106 are provided in the same layer, it is easier to predict and controlthe height difference under the sealant region at a designing phase.

[0078] The first inter-layer film 112 may be a silicon oxide film, asilicon nitride film or a multi-layer film which is a combinationthereof. The resin inter-layer film 113 is made of organic resin such asacrylic or polyimide and is formed through deposition using a spincoating process or the like.

[0079] When the adjustment layer 106 is fabricated at a step differentfrom those for other lines in the same layer, more fine adjustment of aheight difference can be carried out, though the number of stepsincreases.

[0080] While the adjustment layer 106 is provided with a width (the sizein the transverse direction of the sealant) greater than that of thesealant 105 along the sealant 105 in the present embodiment, the widthmay be smaller than that of the sealant 105. Further, it is notessential to provide the adjustment layer 106 along the sealant 105, andit may be provided in any position under the region where the sealant isprovided as long as the height difference is reduced.

[0081] Although the adjustment layer 106 is provided along the sealant105 in the region where the injection hole 110 is provided in FIG. 1, itmay be continuous even in the region where the injection hole isprovided as indicated by the dotted line 120. A substantially constantelectric potential can be achieved in the plane of the substrate whenthe adjustment 106 is provided continuously to surround the peripheraldriving circuits 104 and the active matrix display circuit 103 asdescribed above. This is true only when the adjustment layer 106 hasconductivity.

[0082] The use of an insulating substrate made of glass, quartz or thelike is liable to cause localization of electrostatic charges in theplane of the substrate. As a result, electrostatic breakdown of TFTs maybe caused by localized electrostatic charges during a rubbing step. Asubstantially constant electric potential can be established in theplane of the substrate by forming the adjustment layer 106 continuouslysuch that it surrounds the peripheral driving circuits 104 and activematrix display circuit 103 to prevent such electrostatic breakdown.

[0083] Stripes attributable to the rubbing step sometimes appear on afinished liquid crystal display. By forming a continuous adjustmentlayer 106 as described above, such stripes due to rubbing areadvantageously reduced on the display, although the reason is unknown.

[0084] When the adjustment layer 106 is continuously formed as describedabove, the position of the injection hole 110 is not limited by theshape of the adjustment layer 106, and the hole may be provided in anyposition. However, the height of the path extending from the injectionhole 110 to the interior of the sealant region may be increased becauseof the presence of the adjustment layer 106, resulting in an increase inthe time required for injecting liquid crystal. In other words, theliquid crystal injection time can be reduced by forming the adjustmentlayer 106 in compliance with the shape of the injection hole 110 asshown in FIG. 1 to make the opening area of the injection hole larger.

[0085] While it is not possible to form the adjustment layer 106 suchthat it continuously extend to surround the substrate 101 completelybecause of the presence of the external connection lines 108, it canstill provide the effect of establishing a substantially constantelectric potential in the plane of the substrate even if it is notcompletely continuous. A more constant electric potential can beachieved by, for example, forming the adjustment layer 106 in theconfiguration shown in FIGS. 1, 2A and 2B and providing conductive linesextending along the periphery of the substrate to establish a constantelectric potential in a layer separate from the adjustment layer 106,e.g., under the first inter-layer film 112 shown in FIG. 2B.

[0086] While the external connection lines 108 and adjustment layer 106are provided under the resin inter-layer film 113, i.e., provided in thelayer above the first inter-layer film 112 in the first embodiment, theymay alternatively be provided under the first inter-layer film 112.

EXAMPLE 2

[0087] The second embodiment refers to another configuration of theadjustment layer 106 according to the first embodiment. FIGS. 3A and 3Bshow the configuration of an adjustment layer 301 according to thepresent embodiment.

[0088] Referring to FIG. 3A, the adjustment layer 301 has the same widthw1 as the external connection lines 108 and is formed in sections atintervals w2 instead of being formed continuously as the adjustmentlayer 106 of the first embodiment. Specifically, a region having theexternal connection lines 108 and a region having the adjustment layer301 have the same structure under the sealant 105.

[0089] In such a configuration, the height of the resin inter-layer film112 can be kept substantially equal between the region having theexternal connection lines 108 and the region having the adjustment layer301. This makes it possible to make the region under the sealant 105flatter and to therefore achieve a more uniform height compared to theconfiguration according to the first embodiment. Therefore, thedistortion of the counter substrate 102 is minimized to allow preferabledisplay having quite high uniformity in the screen and less variation.

EXAMPLE 3

[0090] The third embodiment refers to an alternative to theconfiguration described as the first embodiment, in which the resistanceof the external connection lines is reduced. FIGS. 4A and 4B show aconfiguration according to the third embodiment.

[0091]FIG. 4A is a schematic sectional view taken along the line X-X′ inFIG. 1 illustrating the application of the configuration of the thirdembodiment to the configuration of the first embodiment.

[0092] While the external connection lines are provided between thefirst inter-layer film 112 and resin inter-layer film 113 in the firstembodiment, according to the third embodiment, auxiliary lines 401 thatextend along external connection lines 403 are provided under the firstinter-layer film 112 and the external connection lines 403 and auxiliarylines 401 are electrically connected in parallel by forming contactholes in the first inter-layer film 112 to reduce the electricalresistance as shown in FIG. 4A. The auxiliary lines 401 may be formed inother layers to reduce electrical resistance further.

[0093] Referring to FIG. 4A, the external connection lines 403 areelectrically connected to an FPC (flexible printed circuit) 107 throughcontact holes provided in the resin inter-layer film 113 through an ITO(indium tin oxide) film 114. In the present embodiment, the ITO film 114is fabricated at the same step as for an ITO film that forms pixelelectrodes connected to the TFTs of the active matrix display circuit.The ITO film 114 is electrically connected to external circuits throughthe FPC 107.

[0094] Among signals applied to the external connection lines 403 fromthe external circuits, clock and video signals have very highfrequencies. An active matrix liquid crystal display device has a largearea for display, lines forming its circuit inevitably have a length ofseveral centimeters or more. However, since the lines themselves haveonly a thickness in the range from a few hundred nm to 700 nm, the linesas a whole have high electric resistance even if a metal such asaluminum having high conductivity is used as the line material. A highline resistance causes delay and deterioration of the propagation ofhigh frequency signals such as clock and video signals to disallowpreferable display.

[0095] The configuration described in the present embodiment makes itpossible to reduce electrical resistance of the external connectionlines 403 significantly to allow an active matrix liquid crystal displayintegral with peripheral driving circuits to provide preferable displaywhen driven at a high frequency and a high speed.

[0096] However, in such a configuration wherein a plurality of linesprovided in different layers are connected in parallel, a heightdifference between a region under the sealant including the lines and aregion including no line will be greater than that in a case where thoselines are formed only in one layer.

[0097] That is, preferable display can not be achieved due to theincreased height difference in the region under the sealant, thoughelectric resistance is reduced.

[0098] In the configuration according to the present embodiment, anadjustment layer having the same thickness (height) as the auxiliarylines 401 is provided in the same layer as the auxiliary lines 401provided in order to reduce electric resistance, and the auxiliary lines401 and a first adjustment layer 402 are provided in a layer under thefirst inter-layer film 112. Like the first embodiment, the externalconnection lines 403 and a second adjustment layer 404 are providedabove the first inter-layer film 112, i.e., under the resin inter-layerfilm 113.

[0099] In such a configuration wherein auxiliary lines 401 are providedto reduce electrical resistance, the height difference under the sealantregion can be reduced, and uniform display can be achieved in one screenwithout variation.

[0100] In the present embodiment, either or both of the first adjustmentlayer 402 and the second adjustment layer 404 may be configured to havethe same width and intervals as those of the external connection lines403 as shown in the second embodiment. Such a configuration makes itpossible to reduce the height difference under the sealant regionfurther to achieve higher uniformity. In this case, when the auxiliarylines 401 and external connection lines 403 have different widths andintervals, the first adjustment layer 402 and second adjustment layer404 may be formed such that they respectively have the same widths andintervals as the auxiliary lines 401 and external connection lines 403to reduce the height difference under the sealant region for higheruniformity, thereby allowing preferable display.

[0101] In the present embodiment, the auxiliary lines and externalconnection lines may be replaced with each other to use the linesprovided in the layer under the first inter-layer film as externalconnection lines which establish electrical connection with the FPC.

EXAMPLE 4

[0102] The fourth embodiment refers to a configuration wherein a heightdifference under the sealant region is reduced to achieve a uniformheight in case where lines having different widths and intervals arepresent in the same layer. FIG. 5 shows a configuration of an activematrix liquid crystal display device according to the fourth embodiment.In FIG. 5, reference numbers same as those appear in FIG. 1 indicatelike elements.

[0103] Referring to FIG. 5, an active matrix display circuit 103 isdifferent from that shown in FIG. 1 in that one peripheral drivingcircuit 509 such as a shift register or decoder for driving the activematrix display circuit 103 is provided for driving each of the signallines and scanning lines.

[0104] There is provided scanning line short rings 503 which areextensions of the scanning lines and signal line short rings 504 whichare extensions of the signal lines on the sides where the peripheraldriving circuit 509 is not provided. The short rings 503 and 504 areelectrically connected to each other until the substrate is divided intopanels at a multi-shot production step to provide a function ofpreventing the electrostatic breakdown of the TFTs forming the activematrix display circuit 103 at steps where static electricity can occursuch as the rubbing step.

[0105] Since the short rings 503 and 504 are extensions of the scanninglines and signal lines respectively, the widths and intervals of thoselines (a short ring is also described as a line in this specification,although it does not transmit any electric signal in a liquid crystaldisplay device) also the same as those of the scanning lines and signallines. Therefore, the lines have a width in the range from 2 μm to 10 μmand an interval in the range from about 20 μm to about 100 μm which isequal to the pitch of the pixels. Those values obviously changedepending on the application. In general, the scanning line short rings503 and signal line short rings 504 are respectively connected to thegates and sources of the TFTs forming the active matrix display circuit103.

[0106] It would be noted here that the line intervals of the short rings503 and 504 are very much larger than the widths of those lines. This isquite contrary to the external connection lines 108.

[0107]FIG. 6A shows an enlarged view of the region B 505 in FIG. 5, andFIG. 6B shows a section taken along the line B-B′ in FIG. 6A.

[0108]FIG. 7A shows an enlarged view of the region C 506 in FIG. 5, andFIG. 7B shows a section taken along the line C-C′ in FIG. 7A. FIG. 8Ashows an enlarged view of the region D 507 in FIG. 5, and FIG. 8B showsa section taken alone the line D-D′ in FIG. 8A.

[0109] As shown in FIG. 6A, a plurality of external connection lines 108having a predetermined width w1 at predetermined intervals w2 areprovided as a group in a concentrated fashion. The width w1 is in therange from 50 μm to 300 μm, e.g., 200 μm, and the interval w2 is in therange from 30 μm to 100 μm, e.g., 50 μm, in the present embodiment.

[0110] As shown in FIG. 6B, a first inter-layer film 112 and a resininter-layer film 113 are provided on a substrate 101 made of glass,quartz, silicon wafer or the like with an underlying film 111constituted by a silicon oxide film or the like interposed therebetween,and a sealant 105 is provided thereon. An orientation film (not shown)may be provided between the sealant 105 and the resin inter-layer film113.

[0111] As apparent from FIG. 6B, a first adjustment layer 501 isprovided between the underlying film 111 and first inter-layer film 112.This will be described later in more detail.

[0112] As apparent from FIG. 6B, external connection lines 108 and asecond adjustment layer 502 are formed in the same layer from the samematerial, e.g., aluminum between the first inter-layer film 112 and theresin inter-layer film 113 under the sealant 105.

[0113] Therefore, the second adjustment layer 502 has the same thickness(height) as the external connection lines 108 such that a region wherethe external connection lines 108 are not provided under the resininter-layer film 113 has the same height as the external connectionlines 108.

[0114] Such a configuration reduces the height difference between theregion having the external connection lines 108 and the region having noexternal connection lines on the upper surface of the resin inter-layerfilm 113 under the region where the sealant 105 is provided. As aresult, distortion of the counter substrate is reduced when it is puttogether.

[0115] While the second adjustment layer 502 has a configuration thatseems like a continuous line, the external connection lines 108 has theintervals w2. Therefore, the region above the resin inter-layer film 113and under the sealant where the external connection lines 108 areprovided is slightly lower than the region where the second adjustmentlayer 502 is provided, which may cause a height difference. However,since the width w1 of the external connection lines 108 is sufficientlygreater than the interval w2 thereof, the height difference is quitesmall. The present embodiment is similar to the first embodiment up tothis point.

[0116] Next, as shown in FIG. 7A which is an enlarged view of the regionC 506, the present embodiment includes a signal line short ring 504provided in the same layer as the external connection lines 108 andsecond adjustment layer 502.

[0117] The signal line short ring 504 has a width w3 and an interval w4in general but has a width w5 greater than the width w3 and an intervalw6 smaller than the interval w5 in the region under the sealant 105. Thewidth w5 is preferably greater than the interval w6. Preferably, thewidth w5 is as large as possible.

[0118] In such a configuration a height difference on the upper surfaceof the resin inter-layer film 113 in the region under the sealant 105can be reduced between the region where a plurality of signal shortrings 504 are provided as a group and the region where the plurality ofexternal connection lines 108 are provided as a group.

[0119] In other words, in such a configuration, the ratio in a unit areaof the region having the short rings 504 to the region having no shortring in the region where the plurality of signal short rings 504 areprovided as a group under the sealant 105 is made as close as possibleto the ratio in the unit area of the region having the externalconnection lines 108 to the region having no external connection line inthe region where the plurality of external connection lines 108 areprovided as a group.

[0120] Next, as shown in FIG. 8A which is an enlarged view of the regionD 507 and FIG. 8B which is a section taken along the line D-D′ thereof,the first adjustment layer 501 is provided in the same layer as thescanning line short rings 503 as has the same thickness (height). Thescanning line short rings 503 and the first inter-layer film 501 areformed with the same width w3 and interval w4. That is, in the presentembodiment, the first adjustment layer 501 is the same as the scanningline short rings 503 except that it has a different line length.

[0121] In such a configuration, a height difference on the upper surfaceof the first inter-layer film 112 in the region under the sealant 105can be reduced between the region having the scanning line short rings503 and the region having no scanning line short ring to achieve auniform height. That is, the formation of the short rings 503substantially causes no problem associated with the height difference onthe first inter-layer film 112 under the sealant 105.

[0122] Since the line interval w4 of the scanning line short rings 503is very much greater than the line width w3 thereof, when the firstadjustment layer 501 has a continuous configuration like that of theadjustment layer 106 in the first embodiment, the upper surface of thefirst inter-layer film 112 will be higher in the region having thescanning line short rings 503 than in the region having first adjustmentlayer 501.

[0123] According to the present embodiment, the fabrication of thesecond adjustment layer 502 in a step different from those for otherlines in the same layer will allow finer adjustment of the heightdifference, although the number of steps will increase.

[0124] While the first adjustment layer 501 and second adjustment layer502 in the present embodiment are provided along the sealant 105 with awidth greater than that of the sealant 105 (the size in the transversedirection of the sealant), they may be smaller than the sealant inwidth. Further, it is not essential to provide them along the sealant105, and they may be provided in any position under the region where thesealant is provided as long as the height difference is reduced.

[0125] According to the present embodiment, it is advantageous to formthe second adjustment layer 502 with the same configuration as theadjustment layer 106 in the second embodiment instead of a continuousconfiguration to reduce the height difference further.

[0126] According to the present embodiment, when the external connectionlines 108 are provided in the same layer as the first adjustment layer501 and the scanning line short rings 503, the relevant widths andintervals of the adjustment layer and short rings may be changed tothose in the present embodiment.

EXAMPLE 5

[0127] The fifth embodiment shows an example wherein the configurationshown in the fourth embodiment is modified to a configuration withreduced resistance of the external connection lines 403 as shown in thethird embodiment. The present embodiment employs the same configurationsof the external connection lines 403 and auxiliary lines 401 as those inthe third embodiment.

[0128]FIGS. 9A and 9B are an enlarged view and a section taken along theline D-D′ of the region D 507 in FIG. 5, respectively, according to thepresent embodiment. The present embodiment is different from the fourthembodiment in that, as shown in FIGS. 9A and 9B, the scanning line shortrings 503 under the first inter-layer film 112 have an increased widthand decreased intervals in the region under the sealant like the signalline short rings 504 shown in FIGS. 7A and 7B according to the fourthembodiment (The sealant 105 is as shown in the drawings described so faralthough not shown in FIG. 9A).

[0129] The reason for the above-described configuration is that a heightdifference on the upper surface of the resin inter-layer film 113 in theregion under the sealant 105 can be reduced between the region where aplurality of scanning line short rings 503 are provided as a group andthe region where a plurality of auxiliary lines 401 for the externalconnection lines 403 are provided as a group.

EXAMPLE 6

[0130] The sixth embodiment shows a configuration wherein capacitancebetween short rings and an adjustment layer is reduced in a region wherethey face each other.

[0131]FIGS. 10A and 10B are an enlarged view and a sectional view takenalong the line D-D′ of the region D 507 in FIG. 5 according to thepresent embodiment.

[0132] In FIG. 9A associated with the fifth embodiment, the secondadjustment layer 502 faces the scanning line short rings 503 inelectrical and physical continuity thereto. The first inter-layer film112 is present between them. Since the first inter-layer film 112 is aninsulating film constituted by a silicon oxide film, a silicon nitridefilm or a multi-layer film consisting thereof, capacitance is formedbetween the scanning line short rings 503 and the second adjustmentlayer 502 because the second adjustment layer 502 is a conductor.However, since the scanning line short rings 503 are extensions of thescanning lines of the active matrix display circuit 103, the presence ofthe above-described capacitance increases the load required to drive thescanning lines, adversely affecting the display.

[0133] In order to solve such a problem, according to the presentembodiment, the second adjustment layer 502 is divided into independentsegments in electrical isolation from each other in positions where theyface respective scanning line short rings 503 as shown in FIGS. 10A and10B. Specifically, the second adjustment layer 502 is divided intosegments having substantially the same configuration as the scanningline short rings 503 in positions where they face the respectivescanning line short rings 503. As a result, the capacitance can bereduced without increasing the height difference under the sealant.

[0134] Such a configuration can be applied to the first adjustment layer501 facing the signal line short rings 504 to achieve the same effect.

[0135] Further, such a configuration may be applied to the configurationaccording to the fourth embodiment where the width of the scanning lineshort rings 503 is not increased, though the effect is somewhat reduced.

EXAMPLE 7

[0136] The seventh embodiment is an alternative to the configurationaccording to the sixth embodiment. A configuration according to theseventh embodiment is shown in FIGS. 11A and 11B. In the presentembodiment, a scanning line short ring 503 is shaped such that its areavaries in the transverse direction of the sealant. Such a configurationis also effective in reducing capacitance without increasing the heightdifference under the sealant.

[0137] Such a configuration may be applied to the first adjustment layer501 that faces the signal line short rings 504 to achieve the sameeffect.

EXAMPLE 8

[0138] The eighth embodiment shows an alternative to the configurationsaccording to the sixth and seventh embodiments. A configurationaccording to the eighth embodiment is shown in FIG. 12.

[0139] Although the configurations according to the sixth and sevenembodiments are effective in reducing capacitance, when one scanningline short ring 503 is shorted with the second adjustment layer 502 by aspacer or the like which penetrates through the resin inter-layer filmbecause of a pressure applied thereto, the short ring will havecapacitance which is different in magnitude from those of other scanningline short rings. As a result, shorted line will have a driving loaddifferent from those of other scanning lines and have different displaycharacteristics.

[0140] According to the eighth embodiment, a region of the secondadjustment layer 502 that faces one scanning line short ring 503 isfurther divided into a plurality of segments. As a result, even when oneof the plurality of divided second adjustment layers 502 facing onescanning line short ring 503 is shorted, the second adjustment layers502 are not shorted as a whole, and the difference is capacity fromthose of other scanning line short rings 503 can be suppressed tosuppress variations and differences in display characteristics.

EXAMPLE 9

[0141] The present embodiment refers to products utilizing active matrixliquid crystal display devices as described in the above embodiments.Electronic apparatuses that may embody the invention include videocameras, still cameras, projectors, head mount displays, car navigationsystems, personal computers, personal digital assistants (mobilecomputers and cellular mobile phones) and the like. FIGS. 15A through15F are schematic external views of electronic apparatuses according tothe present embodiment.

[0142]FIG. 15A shows a mobile computer which is constituted by a mainbody 2001, a camera portion 2002, an image-receiving portion 2003,operation switches 2004 and a liquid crystal display device 2005.

[0143]FIG. 15B shows a head mount display which is constituted by a mainbody 2101, a pair of liquid crystal display devices 2102 and a bandportion 2103 for securing the main body on the head of a person. Thepair of liquid crystal display devices display images for the left andright eyes, respectively. The user gets visual perception of the imagesthrough an optical system. Then, the user get visual perception whichseems like a large screen spreading in front of his or her eyes.

[0144]FIG. 15C shows a cellular mobile phone which is constituted by amain body 2201, a speech output portion 2202, a speech input portion2202, a liquid crystal display device 2204, operation switches 2205 andan antenna 2206.

[0145]FIG. 15D shows a video camera which is constituted by a main body2301, a reflection type liquid crystal display device 2302, a speechinput portion 2303, operation switches 2304, a battery 2305 and animage-receiving portion 2306.

[0146]FIG. 15E shows a rear type projector in which light emitted by alight source 2402 provided in a main body 2401 is reflected andmodulated by a pixel portion in a reflection type liquid crystal displaydevice 2403. The reflected light is projected through a mirror 2404 and2405 upon a screen 2406 to be displayed thereon as an image.

[0147]FIG. 15F shows a front type projector in which light emitted by alight source 2502 in a main body 2501 is modulated and transmitted by atransmission type liquid crystal display device 2503. The transmittedlight is projected by an optical system 2504 upon a screen 2505 todisplay an image thereon.

[0148] The invention disclosed in this specification makes it possibleto reduce a height difference in a sealant region when lines are presentunder the sealant region, thereby allowing distortion of a countersubstrate to be eliminated and allowing a liquid crystal display devicehaving excellent uniformity of display in a screen to be provided.

What is claimed is:
 1. A liquid crystal display device comprising: asubstrate having an active matrix circuit and peripheral drivingcircuits provided thereon; a counter substrate having a counterelectrode provided above said substrate in a face-to-face relationshiptherewith; a sealant disposed between said substrate and said countersubstrate such that it surrounds said active matrix display circuit andsaid peripheral driving circuits; a liquid crystal material providedinside said sealant; a plurality of external connection lines providedon said substrate under said sealant with a resin inter-layer filminterposed therebetween for electrically connecting said active matrixdisplay circuit, said peripheral driving circuits and circuits which arepresent outside said sealant; and an adjustment layer provided in thesame layer as said plurality of external connection lines.
 2. The liquidcrystal display device according to claim 1 , wherein said adjustmentlayer is formed with the same thickness as that of said plurality ofexternal connection lines.
 3. The liquid crystal display deviceaccording to claim 1 , wherein said adjustment layer is formed with thesame width and intervals as the width and intervals of said plurality ofexternal connection lines.
 4. The liquid crystal display deviceaccording to claim 1 , wherein at least one of said plurality ofexternal connection lines is electrically connected in parallel to oneof a plurality of auxiliary lines provided in a layer different fromthat of said external connection lines.
 5. The liquid crystal displaydevice according to claim 1 , further comprising a plurality of linesextending across said sealant thereunder and having a width smaller thanthat of each of said plurality of external connection lines andintervals greater than said width provided in a layer different fromthat of said plurality of external connection lines, wherein saidplurality of lines include extensions of scanning lines and signal linesthat form said active matrix display circuit.
 6. The liquid crystaldisplay device according to claim 1 , further comprising: a plurality oflines extending across said sealant thereunder and having a widthsmaller than that of each of said plurality of external connection linesand intervals greater than said width provided in the same layer as thatof said plurality of external connection lines, wherein said pluralityof lines include extensions of scanning lines and signal lines that formsaid active matrix display circuit; and said plurality of lines includeportions under said sealant where said width is increased.
 7. The liquidcrystal display device according to claim 4 , further comprising: aplurality of first lines extending across said sealant thereunder andhaving a width smaller than that of each of said plurality of externalconnection lines and intervals greater than said width provided in thesame layer as that of said plurality of external connection lines, saidplurality of first lines including extensions of either scanning linesor signal lines that form said active matrix display circuit; and aplurality of second lines extending across said sealant thereunder andhaving a width smaller than that of each of said plurality of externalconnection lines and intervals greater than said width provided in thesame layer as that of said plurality of external connection lines, saidplurality of second lines including extensions of the other group oflines, i.e., the scanning lines or signal lines that form said activematrix display circuit, said plurality of lines including portions undersaid sealant where said width is increased.
 8. The liquid crystaldisplay device according to claim 7 , wherein said extensions of eitherthe scanning lines or signal lines forming said active matrix displaycircuit are provided in a face-to-face relationship with an adjustmentlayer provided in a layer different from that of either of said scanningand signal lines.
 9. The liquid crystal display device according toclaim 8 , wherein a region of said adjustment layer which faces saidextensions of either the scanning lines or signal lines is electricallyisolated from other regions adjacent thereto.
 10. The liquid crystaldisplay device according to claim 9 , wherein said region of saidadjustment layer which faces said extensions of either the scanninglines or signal lines is electrically divided into a plurality ofregions.
 11. The liquid crystal display device according to claim 7 ,wherein said extensions of the other group of lines, i.e., the scanninglines or signal lines forming said active matrix display circuit areprovided in a face-to-face relationship with an adjustment layerprovided in a layer different from that of the other group of lines,i.e., the scanning lines or signal lines.
 12. The liquid crystal displaydevice according to claim 11 , wherein a region of said adjustment layerwhich faces said extensions of the other group of lines, i.e., thescanning lines or signal lines is electrically isolated from otherregions adjacent thereto.
 13. The liquid crystal display deviceaccording to claim 12 , wherein said region of said adjustment layerwhich faces said extensions of the other group of lines, i.e., thescanning lines or signal lines is electrically divided into a pluralityof regions.
 14. A mobile computer using the liquid crystal displaydevice according to claim 1 .
 15. A head mount display using the liquidcrystal display device according to claim 1 .
 16. A cellular mobilephone using the liquid crystal display device according to claim 1 . 17.A video camera using the liquid crystal display device according toclaim 1 .
 18. A rear type projector using the liquid crystal displaydevice according to claim 1 .
 19. A front type projector using theliquid crystal display device according to claim 1 .
 20. A liquidcrystal display device comprising: a first substrate; an active matrixcircuit provide on said first substrate; a driving circuit provided onsaid first substrate for driving said active matrix circuit; a wiringprovided on said first substrate for supplying signals to said drivingcircuit from an outside of said liquid crystal display device whereinsaid wiring comprises a plurality of conductive layers; a countersubstrate facing said first substrate with a liquid crystal materialinterposed therebetween; a sealant disposed between said first substrateand said counter substrate wherein said wiring extends across saidsealant; and an adjustment layer located between said sealant and saidfirst substrate wherein said adjustment layer has a same thickness assaid plurality of conductive layers.
 21. A liquid crystal deviceaccording to claim 20 wherein said adjustment layer is formed on a samelevel as said wiring.
 22. A mobile computer using the liquid crystaldisplay device according to claim 21 .
 23. A head mount display usingthe liquid crystal display device according to claim 21 .
 24. A cellularmobile phone using the liquid crystal display device according to claim21 .
 25. A video camera using the liquid crystal display deviceaccording to claim 21 .
 26. A rear type projector using the liquidcrystal display device according to claim 21 .
 27. A front typeprojector using the liquid crystal display device according to claim
 21. 28. A liquid crystal display device comprising: a first substrate; anactive matrix circuit provide on said first substrate; a driving circuitprovided on said first substrate for driving said active matrix circuit;a wiring provided on said first substrate for supplying signals to saiddriving circuit from an outside of said liquid crystal display devicewherein said wiring is formed from a conductive film; a countersubstrate facing said first substrate with a liquid crystal materialinterposed therebetween; a sealant disposed between said first substrateand said counter substrate wherein said wiring extends across saidsealant; and an adjustment layer located between said sealant and saidfirst substrate wherein said adjustment layer is formed from saidconductive film.
 29. A liquid crystal device according to 28 whereinsaid adjustment layer is electrically floating.
 30. A liquid crystaldevice according to claim 28 wherein said adjustment layer is formed ona same level as said wiring.
 31. A mobile computer using the liquidcrystal display device according to claim 28 .
 32. A head mount displayusing the liquid crystal display device according to claim 28 .
 33. Acellular mobile phone using the liquid crystal display device accordingto claim 28 .
 34. A video camera using the liquid crystal display deviceaccording to claim 28 .
 35. A rear type projector using the liquidcrystal display device according to claim 28 .
 36. A front typeprojector using the liquid crystal display device according to claim 28.